ACID PROTEINASE SECRETED BY CANDIDA-TROPICALIS - VIRULENCE IN MICE OFA PROTEINASE NEGATIVE MUTANT

The relationship between the ability to secrete a specific acid protei nase (ACP) by Candida tropicalis in the presence of bovine serum album in as a nitrogen source and virulence for mice was studied using two s table proteinase-positive and proteinase-negative strains (DSY68 and D SY65), which were constructed from the wild-type pathogenic yeast C tr opicalis ATCC 750. The inactivation of the gene encoding the secreted acid proteinase was produced by targeted gene disruption. Mortality ra te was slightly lower in groups of mice infected with the proteinase-n egative mutant. All other parameters analysed were similar for two str ains of yeast. Our results therefore conclude that the ACP secreted by C tropicalis did not contribute significantly to fungal virulence in systemic infections.